Coffee (Coffea sp.) bean variety and harvesting periods are factors that directly affect its overall quality. In this study, we investigated the effects of four different harvesting periods (December, January, February and March) on the physicochemical and sensory properties of two coffee bean Catimor varieties (7963 and T8667) planted in the same orchard. Physiological characteristics were significantly affected by the delay in harvest periods, specifically the physicochemical properties of each coffee bean variety between the periods. For the green 7963 variety, the defect rate decreased from 11.08% to 4.19% while chlorogenic acid content increased from 3.78% to 4.99% as the harvest period was delayed. The 7963 variety harvested in February and March and T8667 variety harvested in February had the best quality performance, and their cupping scores were significantly higher than those harvested in other periods. Furthermore, a high correlation was found between physical attributes (defect rate, thousand-grain weight, and green bean size), chemical components (lipids, proteins, chlorogenic acid, caffeine, and trigonelline) and cupping scores.

This study focuses on the storage process of coffee beans, employing electron beam irradiation (EBI) to investigate the comprehensive effects of different irradiation doses on coffee beans and their storage process, including physicochemical indicators, microbial abundance, and flavor compounds. The results showed that a 2 kGy dose of EBI could effectively reduce the total number of bacteria, molds, and yeasts in green coffee beans (GCBs), while a dose of 4 kGy can completely inactivate the bacteria and maintain this effect for one month. Compared with the control sample that has not undergone processing by EBI (CK), the crude fat content of the irradiated samples decreased, accompanied by a significant increase in acid value. After 30 days of storage, compared with the CK-30 sample, EBI treatment significantly reduced both the moisture content and overall brightness value of GCB. The analysis of aroma compounds in roasted coffee beans (RCBs) revealed that substances related to Maillard reaction, caramelization reaction and sugar degradation, such as 2-Furanmethanol and acetic acid, changed in the irradiated samples, but had no significant effect on the characteristic components like caffeine and the aroma detected by the electronic nose. The obtained results provide a scientific basis for applying irradiation technology to the preservation of coffee beans.